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First Map of Alien World
| Title |
First Map of Alien World |
| Description |
This is the first-ever map of the surface of an exoplanet, or a planet beyond our solar system. The map, which shows temperature variations across the cloudy tops of a gas giant called HD 189733b, is made up of infrared data taken by NASA's Spitzer Space Telescope. Hotter temperatures are represented in brighter colors. HD 189733b is what is known as a hot-Jupiter planet. These sizzling, gas planets practically hug their stars, orbiting at distances that are much closer than Mercury is to our sun. They whip around their stars quickly, for example, HD 189733b completes one orbit in just 2.2 days. Hot Jupiters are also thought to be tidally locked to their stars, just as our moon is to Earth. This means that one side of a hot Jupiter always faces its star. As predicted, the map reveals that HD 189733b has a warm spot on its "sunlit" side, which is always pointed toward the star. But the map also shows that this spot is offset from the high-noon, or sun-facing, point by 30 degrees. According to scientists, ferocious winds traveling up to 6,000 miles per hour (nearly 9,700 kilometers per hour) are probably pushing the hot spot to the east. In addition to the warm spot, the map tells astronomers that temperatures on HD 189733b are fairly even all around. While the dark side is about 1,200 degrees Fahrenheit (650 degrees Celsius), the sunlit side is just a bit hotter at 1,700 degrees Fahrenheit (930 degrees Celsius). This mild temperature variation is more evidence for strong winds, since winds would help spread the heat from the hot, sunlit side over to the dark side. These data were collected by Spitzer's infrared array camera as the planet, a so-called transiting planet, passed in front of its star, then swung around and disappeared behind it (see animation). By observing the planet for half of its 2.2-day long orbit, Spitzer was able to measure the infrared light, or heat, coming from its entire surface. The infrared measurements, about a quarter of a million individual data points, were then assembled by scientists into pole-to-pole strips, and ultimately into the complete map shown here. |
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First Map of Alien World
| Title |
First Map of Alien World |
| Description |
This is the first-ever map of the surface of an exoplanet, or a planet beyond our solar system. The map, which shows temperature variations across the cloudy tops of a gas giant called HD 189733b, is made up of infrared data taken by NASA's Spitzer Space Telescope. Hotter temperatures are represented in brighter colors. HD 189733b is what is known as a hot-Jupiter planet. These sizzling, gas planets practically hug their stars, orbiting at distances that are much closer than Mercury is to our sun. They whip around their stars quickly, for example, HD 189733b completes one orbit in just 2.2 days. Hot Jupiters are also thought to be tidally locked to their stars, just as our moon is to Earth. This means that one side of a hot Jupiter always faces its star. As predicted, the map reveals that HD 189733b has a warm spot on its "sunlit" side, which is always pointed toward the star. But the map also shows that this spot is offset from the high-noon, or sun-facing, point by 30 degrees. According to scientists, ferocious winds traveling up to 6,000 miles per hour (nearly 9,700 kilometers per hour) are probably pushing the hot spot to the east. In addition to the warm spot, the map tells astronomers that temperatures on HD 189733b are fairly even all around. While the dark side is about 1,200 degrees Fahrenheit (650 degrees Celsius), the sunlit side is just a bit hotter at 1,700 degrees Fahrenheit (930 degrees Celsius). This mild temperature variation is more evidence for strong winds, since winds would help spread the heat from the hot, sunlit side over to the dark side. These data were collected by Spitzer's infrared array camera as the planet, a so-called transiting planet, passed in front of its star, then swung around and disappeared behind it (see animation). By observing the planet for half of its 2.2-day long orbit, Spitzer was able to measure the infrared light, or heat, coming from its entire surface. The infrared measurements, about a quarter of a million individual data points, were then assembled by scientists into pole-to-pole strips, and ultimately into the complete map shown here. |
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A Real Shiner
| Description |
A Real Shiner |
| Full Description |
Saturn's moon Rhea shows off the moon equivalent of a black eye -- a bright, rayed crater near its eastern limb. Rhea is about half the size of Earth's moon. At 1,528 kilometers (949 miles) across, it is the second-largest moon orbiting Saturn. The image was taken in visible light with the Cassini spacecraft narrow angle camera on Oct. 24, 2004, at a distance of about 1.7 million kilometers (1 million miles) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 40 degrees. The image scale is approximately 10 kilometers (6 miles) per pixel. Cassini will image this hemisphere of Rhea again in mid-January 2005, just after the Huygens probe landing on Titan - with approximately 1-kilometer (0.6-mile) resolution. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo. For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the Cassini imaging team home page, http://ciclops.org . *Image Credit:* NASA/JPL/Space Science Institute |
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The Veils of Titan
| Description |
Here on the Gallery page you can find the very latest images, videos and products from the Cassini-Huygens mission to Saturn, including the spectacular launch, spacecraft assembly and the exciting trip to Saturn. |
| Full Description |
The veils of Saturn's most mysterious moon have begun to lift in Cassini's eagerly awaited first glimpse of the surface of Titan, a world where scientists believe organic matter rains from hazy skies and seas of liquid hydrocarbons dot a frigid surface. Surface features previously observed only from Earth-based telescopes are now visible in images of Titan taken in mid-April by Cassini through one of the narrow angle camera's spectral filters specifically designed to penetrate the thick atmosphere. The image scale is 230 kilometers (143 miles) per pixel, and it rivals the best Earth-based images. The two images displayed here show Titan from a vantage point 17 degrees below its equator, yielding a view from 50 degrees north latitude all the way to its south pole. The image on the left was taken four days after the image on the right. Titan rotated 90 degrees in that time. The two images combined cover a region extending halfway around the moon. The observed brightness variations suggest a diverse surface, with variations in average reflectivity on scales of a couple hundred kilometers. The images were taken through a narrow filter centered at 938 nanometers, a spectral region in which the only obstacle to light is the carbon-based, organic haze. Despite the rather long 38-second exposure times, there is no noticeable smear due to spacecraft motion. The images have been magnified 10 times and enhanced in contrast to bring out details. No further processing to remove the effects of the overlying atmosphere has been performed. The superimposed grid over the images illustrates the orientation of Titan -- north is up and rotated 25 degrees to the left -- as well as the geographical regions of the satellite that are illuminated and visible. The yellow curve marks the position of the boundary between day and night on Titan. The enhanced image contrast makes the region within 20 degrees of this day and night division darker than usual. The Sun illuminates Titan from the right at a phase angle of 66 degrees. Because the Sun is in the southern hemisphere as seen from Titan, the north pole is canted relative to the boundary between day and night by 25 degrees. Also shown here is a map of relative surface brightness variations on Titan as measured in images taken in the 1080-nanometer spectral region in 1997 and 1998 by the Near Infrared Camera and Multi-Object Spectrometer on NASA¿s Hubble Space Telescope. These images have scales of 300 kilometers (186 miles) per pixel. The map colors indicate different surface reflectivities. From darkest to brightest, the color progression is: deep blue (darkest), light blue, green, yellow, red and deep red (brightest). The large, continent-sized, red feature extending from 60 degrees to 150 degrees west longitude is called Xanadu. It is unclear whether Xanadu is a mountain range, giant basin, smooth plain, or a combination of all three. It may be dotted with hydrocarbon lakes but that is also unknown. All that, is presently known is that in Earth-based images, it is the brightest region on Titan. A comparison between the Cassini images and the Hubble map indicates that Xanadu is visible as a bright region in the Cassini image on the right. The dark blue northwest-southeast trending feature from 210 degrees to 250 degrees west longitude, and the bright yellow/green region to the east (right) and southeast of it at minus 50 degrees latitude and 180 to 230 degrees west longitude on the Hubble map, can both be seen in the image on the left. It is noteworthy that the surface is visible to Cassini from its present approach viewing geometry, which is not the most favourable for surface viewing. These early Cassini observations are promising for upcoming imaging sequences of Titan in which the resolution improves by a factor of five over the next two months. These results are encouraging for future, in-orbit observations of Titan that will be acquired from lower, more favorable phase angles. The first opportunity to view small-scale features (2 kilometers or 1.2 miles) on the surface comes during a 350,000 kilometer (217,500 mile) flyby over Titan's south pole on July 2, 2004, only 30 hours after Cassini's insertion into orbit around the ringed planet. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Office of Space Science, Washington, D.C. The Cassini orbiter and its two onboard cameras, were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo. For more information about the Cassini-Huygens mission visit, http://saturn.jpl.nasa.gov and the Cassini imaging team home page, http://ciclops.org . Image Credit: NASA/JPL/Space Science Institute |
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Pale Blue Orb (1)
| Description |
Pale Blue Orb |
| Full Description |
Not since NASA's Voyager 1 spacecraft saw our home as a pale blue dot from beyond the orbit of Neptune has Earth been imaged in color from the outer solar system. Now, Cassini casts powerful eyes on our home planet, and captures Earth, a pale blue orb -- and a faint suggestion of our moon -- among the glories of the Saturn system. Earth is captured here in a natural color portrait made possible by the passing of Saturn directly in front of the sun from Cassini's point of view. At the distance of Saturn's orbit, Earth is too narrowly separated from the sun for the spacecraft to safely point its cameras and other instruments toward its birthplace without protection from the sun's glare. The Earth-and-moon system is visible as a bright blue point on the right side of the image above center. Here, Cassini is looking down on the Atlantic Ocean and the western coast of north Africa. The phase angle of Earth, seen from Cassini is about 30 degrees. A magnified view of the image taken through the clear filter (monochrome) shows the moon as a dim protrusion to the upper left of Earth. Seen from the outer solar system through Cassini's cameras, the entire expanse of direct human experience, so far, is nothing more than a few pixels across. Earth no longer holds the distinction of being our solar system's only "water world," as several other bodies suggest the possibility that they too harbor liquid water beneath their surfaces. The Saturnian moon, Enceladus, is among them, and is also captured on the left in this image (see inset), with its plume of water ice particles and swathed in the blue E ring which it creates. Delicate fingers of material extend from the active moon into the E ring. See Ghostly Fingers of Enceladus, for a more detailed view of these newly-revealed features. The narrow tenuous G ring and the main rings are seen at the right. The view looks down from about 15 degrees above the un-illuminated side of the rings. Images taken using red, green and blue spectral filters were combined to create this view. The image was taken by the Cassini spacecraft wide-angle camera on Sept. 15, 2006, at a distance of approximately 2.1 million kilometers (1.3 million miles) from Saturn and at a sun-Saturn-spacecraft angle of almost 179 degrees. Image scale is 129 kilometers (80 miles) per pixel. At this time, Cassini was nearly 1.5 billion kilometers (930 million miles) from Earth. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov ., The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
September 19, 2006 |
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In Saturn's Shadow (Color-ex
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| Description |
In Saturn's Shadow (Color-exagerated view) |
| Full Description |
+ Original version + Image with labels With giant Saturn hanging in the blackness and sheltering Cassini from the sun's blinding glare, the spacecraft viewed the rings as never before, revealing previously unknown faint rings and even glimpsing its home world. This marvelous panoramic view was created by combining a total of 165 images taken by the Cassini wide-angle camera over nearly three hours on Sept. 15, 2006. The full mosaic consists of three rows of nine wide-angle camera footprints, only a portion of the full mosaic is shown here. Color in the view was created by digitally compositing ultraviolet, infrared and clear filter images and was then adjusted to resemble natural color. The mosaic images were acquired as the spacecraft drifted in the darkness of Saturn's shadow for about 12 hours, allowing a multitude of unique observations of the microscopic particles that compose Saturn's faint rings. Ring structures containing these tiny particles brighten substantially at high phase angles: i.e., viewing angles where the sun is almost directly behind the objects being imaged. During this period of observation Cassini detected two new faint rings: one coincident with the shared orbit of the moons Janus and Epimetheus, and another coincident with Pallene's orbit. (See The Janus/Epimetheus Ring and Moon-Made Rings for more on the two new rings.) The narrowly confined G ring is easily seen here, outside the bright main rings. Encircling the entire system is the much more extended E ring. The icy plumes of Enceladus, whose eruptions supply the E ring particles, betray the moon's position in the E ring's left-side edge. Interior to the G ring and above the brighter main rings is the pale dot of Earth. Cassini views its point of origin from over a billion kilometers (and close to a billion miles) away in the icy depths of the outer solar system. See Pale Blue Orb for a similar view of Earth taken during this observation. Small grains are pushed about by sunlight and electromagnetic forces. Hence their distribution tells much about the local space environment. A second version of the mosaic view is presented here in which the color contrast is greatly exaggerated. In such views, imaging scientists have noticed color variations across the diffuse rings that imply active processes sort the particles in the ring according to their sizes. Looking at the E ring in this color-exaggerated view, the distribution of color across and along the ring appears to be different between the right side and the left. Scientists are not sure yet how to explain these differences, though the difference in phase angle between right and left may be part of the explanation. The phase angle is about 179 degrees on Saturn. The main rings are overexposed in a few places. This view looks toward the unlit side of the rings from about 15 degrees above the ringplane. Cassini was approximately 2.2 million kilometers (1.3 million miles) from Saturn when the, images in this mosaic were taken. Image scale on Saturn is about 260 kilometers (162 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
October 11, 2006 |
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Moons in the Night
| Description |
Moons in the Night |
| Full Description |
Sunlight makes visible the faint band called the E ring as two moons meet in the sky. Enceladus (505 kilometers, or 314 miles across) and Tethys (1,071 kilometers, or 665 miles across) appear close together in the sky in this image, but in reality, Tethys was more than 260,000 kilometers (162,000 miles) farther from the Cassini spacecraft -- greater than half the distance from Earth to the Moon. Enceladus is easy to identify by the brilliant plume of ice erupting from its south pole. Although this perspective views the night sides of both moons, the Sun is not the only source of illumination in the Saturn system. Tethys is at a fuller phase with respect to Saturn, and thus its "night side" is more fully lit than that of Enceladus. The view was acquired from a Sun-Enceladus-spacecraft, or phase, angle of 163 degrees, a viewing geometry in which the microscopic ice particles in its plume brighten substantially. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on June 6, 2006 at a distance of approximately 3.9 million kilometers (2.4 million miles) from Enceladus and 4.2 million kilometers (2.6 million miles) from Tethys. Image scale is 23 kilometers (14 miles) per pixel on Enceladus and 25 kilometers (16 miles) on Tethys. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
April 16, 2007 |
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Cat's eye rings and peek-a-b
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| Description |
On Aug. 16, 2006, as the Cassini orbiter flew directly between the sun and Saturn, its Visual and Infrared Mapping Spectrometer captured a sequence of images that vividly show this opposition brightening. |
| Full Description |
Astronomers have long known that Saturn's rings reflect sunlight most strongly when Earth is located directly between Saturn and the sun. Flat, shiny surfaces (like a mirror or a pond) can appear particularly bright when light reflects off them in a certain direction. Scientists call this "specular reflection," from the Latin word for mirror. However, even rough surfaces, like those of Earth's moon or Saturn's rings, can appear bright when the source of light is directly behind the observer's head, no matter what the orientation of the surface is. This latter phenomenon is known as the "opposition effect." Spectacular examples include the eyes of a cat, which seem to glow brightly when they are illuminated by a flashlight, or highway signs and reflectors that "light up" when they are caught in a car's headlights. On Aug. 16, 2006, as the Cassini orbiter flew directly between the sun and Saturn, its Visual and Infrared Mapping Spectrometer captured a sequence of images that vividly show this opposition brightening. Combined here into a mosaic, the images show -- from left to right -- a small, bright spot moving from the outermost B ring across the Cassini Division and all the way across the A ring. In each image, this spot is centered on the point in the rings directly opposite the sun. Theoretical models for the opposition effect suggest that it can be explained by light being scattered several times within the surfaces of individual, transparent, icy ring particles on scales of about 40 micrometers, or 1/500th of an inch. Similar effects are seen in laboratory studies of bright, finely-textured material such as snow or sugar crystals. In this mosaic, blue colors highlight the icy rings (2.35 microns), green represents sunlight reflected by the clouds of Saturn (2.86 microns) and red depicts thermal emission from the planet's interior (5.02 microns). The rings were observed while they were in front of the planet, producing a complex interplay of sunlight reflected from the rings and the shadows cast by the rings on the cloud tops of Saturn. The yellow-green sunlit clouds of Saturn are seen in the upper right corner of the mosaic beyond the outer edge of the A ring, and also through the 4,000-kilometer-wide (2,400 mile) Cassini Division in the left third of the mosaic. (Yellow indicates a mixture of reflected sunlight and thermal emission.) The shadowed regions of the planet, on the other hand, appear deep red because only thermal emission produced deep inside Saturn itself is visible. At exact opposition, the shadows of the rings are hidden behind the rings themselves, but away from this point shadows can be seen peeking out from behind the edges of the A and B rings into the Cassini Division, as well as beyond the outer edge of the A ring. If one looks closely, one can even trace the A ring's shadow behind the partly transparent A ring, as a faint purple band. Within this band, a thin blue-green line crossing obliquely behind the A ring is, caused by sunlight passing through the narrow Encke Gap in the outer A ring. The Cassini spacecraft was at a distance of 254,000 kilometers (157,800 miles) from the center of Saturn when these images were taken, while the opening angle of the rings to the sun was 16.3 degrees. The image scale at the rings is approximately 70 kilometers (40 miles) per pixel. All nine images were taken over a period of 27 minutes, and the vertical dimension of the mosaic is 1.8 degrees. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The Visual and Infrared Mapping Spectrometer team is based at the University of Arizona, where this image was produced. For more information about the Cassini-Huygens mission, visit: http://saturn.jpl.nasa.gov/home/index.cfm. The visual and infrared mapping spectrometer team home page is at: http://wwwvims.lpl.arizona.edu . Credit: NASA/JPL/University of Arizona |
| Date |
June 26, 2007 |
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Cat's eye rings and peek-a-b
…
| Description |
On Aug. 16, 2006, as the Cassini orbiter flew directly between the sun and Saturn, its Visual and Infrared Mapping Spectrometer captured a sequence of images that vividly show this opposition brightening. |
| Full Description |
See also the non-annotated version. Astronomers have long known that Saturn's rings reflect sunlight most strongly when Earth is located directly between Saturn and the sun. Flat, shiny surfaces (like a mirror or a pond) can appear particularly bright when light reflects off them in a certain direction. Scientists call this "specular reflection," from the Latin word for mirror. However, even rough surfaces, like those of Earth's moon or Saturn's rings, can appear bright when the source of light is directly behind the observer's head, no matter what the orientation of the surface is. This latter phenomenon is known as the "opposition effect." Spectacular examples include the eyes of a cat, which seem to glow brightly when they are illuminated by a flashlight, or highway signs and reflectors that "light up" when they are caught in a car's headlights. On Aug. 16, 2006, as the Cassini orbiter flew directly between the sun and Saturn, its Visual and Infrared Mapping Spectrometer captured a sequence of images that vividly show this opposition brightening. Combined here into a mosaic, the images show -- from left to right -- a small, bright spot moving from the outermost B ring across the Cassini Division and all the way across the A ring. In each image, this spot is centered on the point in the rings directly opposite the sun. Theoretical models for the opposition effect suggest that it can be explained by light being scattered several times within the surfaces of individual, transparent, icy ring particles on scales of about 40 micrometers, or 1/500th of an inch. Similar effects are seen in laboratory studies of bright, finely-textured material such as snow or sugar crystals. In this mosaic, blue colors highlight the icy rings (2.35 microns), green represents sunlight reflected by the clouds of Saturn (2.86 microns) and red depicts thermal emission from the planet's interior (5.02 microns). The rings were observed while they were in front of the planet, producing a complex interplay of sunlight reflected from the rings and the shadows cast by the rings on the cloud tops of Saturn. The yellow-green sunlit clouds of Saturn are seen in the upper right corner of the mosaic beyond the outer edge of the A ring, and also through the 4,000-kilometer-wide (2,400 mile) Cassini Division in the left third of the mosaic. (Yellow indicates a mixture of reflected sunlight and thermal emission.) The shadowed regions of the planet, on the other hand, appear deep red because only thermal emission produced deep inside Saturn itself is visible. At exact opposition, the shadows of the rings are hidden behind the rings themselves, but away from this point shadows can be seen peeking out from behind the edges of the A and B rings into the Cassini Division, as well as beyond the outer edge of the A ring. If one looks closely, one can even trace the A ring's shadow behind the partly transparent A ring, as a faint purple band. Within this band, a thin blue-green line, crossing obliquely behind the A ring is caused by sunlight passing through the narrow Encke Gap in the outer A ring. The Cassini spacecraft was at a distance of 254,000 kilometers (157,800 miles) from the center of Saturn when these images were taken, while the opening angle of the rings to the sun was 16.3 degrees. The image scale at the rings is approximately 70 kilometers (40 miles) per pixel. All nine images were taken over a period of 27 minutes, and the vertical dimension of the mosaic is 1.8 degrees. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The Visual and Infrared Mapping Spectrometer team is based at the University of Arizona, where this image was produced. For more information about the Cassini-Huygens mission, visit: http://saturn.jpl.nasa.gov/home/index.cfm. The visual and infrared mapping spectrometer team home page is at: http://wwwvims.lpl.arizona.edu . Credit: NASA/JPL/University of Arizona |
| Date |
June 26, 2007 |
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Rhea in Saturnshine
| Description |
Rhea in Saturnshine |
| Full Description |
The night side of Rhea shines softly in reflected light from Saturn. A similar effect, called Earthshine, can often be seen dimly illuminating the dark side Earth's moon. Background stars make short, dim trails across the black sky. The sunlit terrain on Rhea is so much brighter than the part lit by Saturn that the former is completely overexposed in this view, which took more than 30 seconds to acquire. This view looks toward the leading hemisphere on Rhea (1,528 kilometers, or 949 miles across). North is up and rotated 28 degrees to the left. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on June 11, 2007. The view was obtained at a distance of approximately 364,000 kilometers (226,000 miles) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 154 degrees. Image scale is 4 kilometers (3 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
July 18, 2007 |
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Bands of Clouds and Lace
| Description |
Here on the Gallery page you can find the very latest images, videos and products from the Cassini-Huygens mission to Saturn, including the spectacular launch, spacecraft assembly and the exciting trip to Saturn. |
| Full Description |
As Cassini nears its rendezvous with Saturn, new detail in the banded clouds of the planet's atmosphere are becoming visible. Cassini began the journey to the ringed world of Saturn nearly seven years ago and is now less than two months away from orbit insertion on June 30. Cassini¿s narrow-angle camera took this image on April 16, 2004, when the spacecraft was 38.5 million kilometers (23.9 million miles) from Saturn. Dark regions are generally areas free of high clouds, and bright areas are places with high, thick clouds which shield the view of the darker areas below. A dark spot is visible at the south pole, which is remarkable to scientists because it is so small and centered. The spot could be affected by Saturn's magnetic field, which is nearly aligned with the planet's rotation axis, unlike the magnetic fields of Jupiter and Earth. From south to north, other notable features are the two white spots just above the dark spot toward the right, and the large dark oblong-shaped feature that extends across the middle. The darker band beneath the oblong-shaped feature has begun to show a lacy pattern of lighter-colored, high altitude clouds, indicative of turbulent atmospheric conditions. The cloud bands move at different speeds, and their irregularities may be due to either the different motions between them or to disturbances below the visible cloud layer. Such disturbances might be powered by the planet's internal heat, Saturn radiates more energy than it receives from the Sun. The moon Mimas (396 kilometers, 245 miles across) is visible to the left of the south pole. Saturn currently has 31 known moons. Since launch, 13 new moons have been discovered by ground-based telescopes. Cassini will get a closer look and may discover new moons, perhaps embedded within the planet¿s magnificent rings. This image was taken using a filter sensitive to light near 727 nanometers, one of the near-infrared absorption bands of methane gas, which is one of the ingredients in Saturn's atmosphere. The image scale is approximately 231 kilometers (144 miles) per pixel. Contrast has been enhanced to aid visibility of features in the atmosphere. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Office of Space Science, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo. For more information about the Cassini-Huygens mission visit, http://saturn.jpl.nasa.gov and the Cassini imaging team home page, http://ciclops.org . Image Credit: NASA/JPL/Space Science Institute |
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| Description |
Here on the Gallery page you can find the very latest images, videos and products from the Cassini-Huygens mission to Saturn, including the spectacular launch, spacecraft assembly and the exciting trip to Saturn. |
| Full Description |
Saturn appears serene and majestic in the first color composite made of images taken by NASA's Cassini spacecraft on its approach to the ringed planet, with arrival still 20 months away. The planet was 285 million kilometers (177 million miles) away from the spacecraft, nearly twice the distance between the Sun and Earth, when Cassini took images of it in various filters as an engineering test on Oct. 21, 2002. It is summer in Saturn's southern hemisphere. The Sun is a lofty 27 degrees below the equator and casts a semi-circular shadow of the planet on the rings. The shadow extends partway across the rings, leaving the outer A ring in sunlight. The last Saturn-bound spacecraft, Voyager 2, arrived in early northern spring. Many features seen in Voyager images -- spoke-like markings on the rings, clouds and eddies in the hazy atmosphere, ring-shepherding moons -- are not yet visible to Cassini. Titan, Saturn's largest moon, appears in the upper left. It is the only moon resolved from this distance. This composite uses a threefold enhancement in the brightness of Titan relative to the brightness of Saturn. Titan is a major attraction for scientists of the Cassini-Huygens mission. They will study its haze-enshrouded atmosphere and peer down, with special instrumentation, to its surface to look for evidence of organic processes similar to those that might have occurred on the early Earth, prior to the emergence of life. Cassini will enter orbit around Saturn on July 1, 2004. It will release a piggybacked probe, Huygens, which will descend through Titan's atmosphere on Jan. 14, 2005. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. Information about the mission is available online at http://saturn.jpl.nasa.gov . The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Office of Space Science, Washington, D.C. *Image Note: * * Credit: NASA/JPL/Southwest Research Institute For higher resolution, click here. |
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| Description |
Here on the Gallery page you can find the very latest images, videos and products from the Cassini-Huygens mission to Saturn, including the spectacular launch, spacecraft assembly and the exciting trip to Saturn. |
| Full Description |
Jupiter's Magnetosphere Made Visible February 27, 2002 The vast magnetosphere of charged particles whirling around Jupiter, normally invisible, can be imaged by a new type of instrument aboard NASA's Cassini spacecraft and is seen here. Three features are sketched in for context: a black circle showing the size of Jupiter, lines of Jupiter's magnetic field, and a cross-section of the Io torus, a doughnut-shaped ring of charged particles that originate from volcanic eruptions on Jupiter's moon Io and circle Jupiter at about the orbit of Io. Jupiter's magnetosphere is the largest object in the solar system. If it glowed in wavelengths visible to the eye, it would appear two to three times the size of the Sun or Moon to viewers on Earth. Cassini's ion and neutral camera detects neutral atoms expelled from the magnetosphere, deriving information about their source. This image was taken shortly after Cassini's closest approach to Jupiter, about 10 million kilometers (6 million miles) from the planet on Dec. 30, 2000. For more information about the Saturn-bound spacecraft and its observations of Jupiter, see the Cassini home page, http://saturn.jpl.nasa.gov. Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini mission for NASA's Office of Space Science, Washington, D.C. Credit: NASA/JPL/Johns Hopkins University Applied Physics Laboratory More information about the Cassini and Galileo joint observations of the Jupiter system is available online at: http://www.jpl.nasa.gov/jupiterflyby. Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Galileo and Cassini missions for NASA's Office of Space Science, Washington, D.C. For higher resolution, click here. |
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Rhea's Memory
| Description |
Saturn's icy moon Rhea |
| Full Description |
The story of the solar system is written upon the faces of its many worlds, such as Saturn's icy moon Rhea, seen here in an image from Cassini. The moon's many impact craters attest to its violent beginnings and more than four billion years of subsequent history. Rhea is 1,528 kilometers (949 miles) across. Most moons in the outer solar system are icy, in contrast to the rocky inner planets and Earth's moon. When the planets and their moons first formed around our Sun, conditions were cold enough at Saturn's distance that ices could condense to form solid bodies like Rhea. Since its formation, Rhea has been battered by the leftover debris of planet building, although at a much lower rate for the past 3.8 billion years or so. North on Rhea is up and rotated about 20 degrees to the left. This view shows principally the leading hemisphere on Rhea. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on May 5, 2005, at a distance of approximately 1.4 million kilometers (900,000 miles) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 78 degrees. The image scale is 9 kilometers (6 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
June 23, 2005 |
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Rings At Opposition
| Description |
Rings At Opposition |
| Full Description |
When Cassini gazes down at Saturn's rings with the Sun directly behind the spacecraft, an unusual phenomenon called the "opposition effect" can be seen. The effect is visible here as a bright region, near right, toward the inner edge of the A ring. The precise nature of the effect at Saturn is still under scrutiny by imaging scientists. However the effect in Saturn's rings can be witnessed from Earth, when the viewing conditions are right. It can also be seen in photographs of the lunar surface taken by the Apollo astronauts. To understand the effect, imagine an observer standing on a dry, sandy beach. When the Sun is directly behind the observer, the shadows cast by the grains in the field of view in front of the observer will fall directly behind the grains and will not be visible. When the Sun is at any other angle relative to the observer, the shadows cast by the grains will be visible to the observer. These shadows in the field of view make the scene a bit darker. This effect would cause a centrally bright spot to appear on the sandy surface in the first case, but not in the second. For Cassini, the opposition effect is seen when the angle between the Sun, the rings and the spacecraft is extremely close to zero. For the sequence of images during which this view was obtained, Cassini maintained this viewing angle and the bright spot appeared to move across the rings with the spacecraft's motion. The moon Janus (181 kilometers, or 113 miles, across) is seen here at lower left. The image was taken in visible light with the Cassini spacecraft wide-angle camera on June 7, 2005, at a distance of approximately 738,000 kilometers (458,000 miles) from Saturn. The image scale is 40 kilometers (25 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org. Credit: NASA/JPL/Space Science Institute |
| Date |
July 15, 2005 |
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Enceladus Temperature Map
| Description |
Enceladus Temperature Map |
| Full Description |
This image shows the surprise that startled Cassini scientists on the composite infrared spectrometer team when they got their first look at the infrared (heat) radiation from the south pole of Saturn's moon Enceladus. There is a dramatic warm spot centered on the pole that is probably a sign of internal heat leaking out of the icy moon. The data were taken during the spacecraft's third flyby of this intriguing moon on July 14, 2005. Based on data from previous flybys, which did not show the south pole well, team members expected that the south pole would be very cold, as shown in the left panel. Enceladus is one of the coldest places in the Saturn system because its extremely bright surface reflects 80 percent of the sunlight that hits it, so only 20 percent is available to heat the surface. As on Earth, the poles should be even colder than the equator because the sun shines at such an oblique angle there. The right hand panel shows a global temperature image made from measurements of Enceladus' heat radiation at wavelengths between 9 and 16.5 microns. Cassini made the observation from a distance of 84,000 kilometers (52,000 miles) on the approach to Enceladus, and the image shows details as small as 25 kilometers (16 miles). Equatorial temperatures are much as expected, topping out at about 80 degrees Kelvin (-315 degrees Fahrenheit), but the south pole is occupied by a well-defined warm region reaching 85 Kelvin (-305 degrees Fahrenheit). That is 15 degrees Kelvin (27 degrees Fahrenheit) warmer than expected. The composite infrared spectrometer data further suggest that small areas of the pole are at even higher temperatures, well over 110 degrees Kelvin (-261 degrees Fahrenheit). Evaporation of this relatively warm ice probably generates the cloud of water vapor detected above Enceladus' south pole by several other Cassini instruments. The south polar temperatures are very difficult to explain if sunlight is the only energy source heating the surface, though exotic sunlight-trapping mechanisms have not yet been completely ruled out. It therefore seems likely that portions of the polar region are warmed by heat escaping from the interior of the moon. This would make Enceladus only the third solid body in the solar system, after Earth and Jupiter's volcanic moon Io, where hot spots powered by internal heat have been detected. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The composite infrared spectrometer team homepage is, http://cirs.gsfc.nasa.gov/ . Credit: NASA/JPL/GSFC |
| Date |
July 29, 2005 |
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Phoebe Temperature Maps
| Description |
Phoebe Temperature Maps |
| Full Description |
A montage of maps of Saturn's moon Phoebe shows surface temperatures at various times of day as determined by the composite infrared spectrometer onboard Cassini during the June 11, 2004, Phoebe flyby. The asterisk on each map shows the location of the subsolar point, where the Sun is directly overhead. This point moves across the surface as Phoebe rotates. It is morning in regions to the left of the subsolar point, and afternoon in regions to the right. Like a newspaper weather map, different colors indicate different temperatures, though Phoebe's temperatures are distinctly cooler than even the coldest January day on Earth. Equatorial temperatures peak in the early afternoon near 112 Kelvin (-257 Fahrenheit), plunging to 78 Kelvin (-319 Fahrenheit) before dawn, and are even colder at higher latitudes. The large day/night temperature contrasts imply that Phoebe's surface is covered in loose dust or ice particles that store little heat and thus cool off rapidly at night. Regions of Phoebe's surface that were not observed are shown in black. Most of the maps show the effect on surface temperatures of the large crater-like depression seen in Cassini's visible-wavelength images of Phoebe, which is located just left of center in these maps. Crater walls that are shadowed and cold in the early morning in the first map are sunlit and warm in the late afternoon in the final map. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Office of Space Science, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the Cassini composite infrared spectrometer home page at http://cirs.gsfc.nasa.gov/ . Image Credit: NASA/JPL/Goddard Space Flight Center |
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Faint Southern Clouds
| Description |
Faint Southern Clouds |
| Full Description |
This clear-filter view of Saturn's moon Titan reveals a region of cloud activity at high southern latitudes. Titan is 5,150 kilometers (3,200 miles) across. Cassini observations have generally been consistent with Earth-based observations that indicate the south-polar fields of clouds that had been observed frequently in 2004 haven't been present in 2005. This image was taken in visible light with the Cassini spacecraft narrow-angle camera on Aug. 31, 2005, at a distance of approximately 3.3 million kilometers (2 million miles) from Titan and at a Sun-Titan-spacecraft, or phase, angle of 70 degrees. The image scale is 20 kilometers (12 miles) per pixel. North on Titan is up and rotated about 20 degrees to the left. The view has been mildly enhanced to make the cloud feature more easily visible. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . *Credit:* NASA/JPL/Space Science Institute |
| Date |
September 29, 2005 |
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Mimas...and Titan Beyond
| Description |
Mimas...and Titan Beyond |
| Full Description |
Titan, Saturn's largest moon, and Mimas, closer but much smaller on the right, are seen together in this view from Cassini. Titan's gravity is weaker than Earth's, so the moon's atmosphere is quite extended -- a quality hinted at in this view. Part of Mimas' dark side is illuminated by reflected light from nearby Saturn. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Dec. 3, 2005, at a distance of approximately 3.6 million kilometers (2.2 million miles) from Titan (5,150 kilometers, or 3,200 miles across) and 2.5 million kilometers (1.6 million miles) from Mimas (397 kilometers, or 247 miles across). Both moons are seen at a Sun-moon-spacecraft angle, or phase angle, of 110 degrees. The image scale is 22 kilometers (14 miles) per pixel on Titan and 15 kilometers (9 miles) per pixel on Mimas. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . *Credit:* NASA/JPL/Space Science Institute |
| Date |
January 3, 2006 |
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In Saturn's Shadow (with lab
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| Description |
In Saturn's Shadow (with labels) |
| Full Description |
+ Original version + Color-exagerated version With giant Saturn hanging in the blackness and sheltering Cassini from the sun's blinding glare, the spacecraft viewed the rings as never before, revealing previously unknown faint rings and even glimpsing its home world. This marvelous panoramic view was created by combining a total of 165 images taken by the Cassini wide-angle camera over nearly three hours on Sept. 15, 2006. The full mosaic consists of three rows of nine wide-angle camera footprints, only a portion of the full mosaic is shown here. Color in the view was created by digitally compositing ultraviolet, infrared and clear filter images and was then adjusted to resemble natural color. The mosaic images were acquired as the spacecraft drifted in the darkness of Saturn's shadow for about 12 hours, allowing a multitude of unique observations of the microscopic particles that compose Saturn's faint rings. Ring structures containing these tiny particles brighten substantially at high phase angles: i.e., viewing angles where the sun is almost directly behind the objects being imaged. During this period of observation Cassini detected two new faint rings: one coincident with the shared orbit of the moons Janus and Epimetheus, and another coincident with Pallene's orbit. (See The Janus/Epimetheus Ring and Moon-Made Rings for more on the two new rings.) The narrowly confined G ring is easily seen here, outside the bright main rings. Encircling the entire system is the much more extended E ring. The icy plumes of Enceladus, whose eruptions supply the E ring particles, betray the moon's position in the E ring's left-side edge. Interior to the G ring and above the brighter main rings is the pale dot of Earth. Cassini views its point of origin from over a billion kilometers (and close to a billion miles) away in the icy depths of the outer solar system. See Pale Blue Orb for a similar view of Earth taken during this observation. Small grains are pushed about by sunlight and electromagnetic forces. Hence their distribution tells much about the local space environment. A second version of the mosaic view is presented here in which the color contrast is greatly exaggerated. In such views, imaging scientists have noticed color variations across the diffuse rings that imply active processes sort the particles in the ring according to their sizes. Looking at the E ring in this color-exaggerated view, the distribution of color across and along the ring appears to be different between the right side and the left. Scientists are not sure yet how to explain these differences, though the difference in phase angle between right and left may be part of the explanation. The phase angle is about 179 degrees on Saturn. The main rings are overexposed in a few places. This view looks toward the unlit side of the rings from about 15 degrees above the ringplane. Cassini was approximately 2.2 million kilometers (1.3 million miles) from Saturn when, the images in this mosaic were taken. Image scale on Saturn is about 260 kilometers (162 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
October 11, 2006 |
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| Description |
Here on the Gallery page you can find the very latest images, videos and products from the Cassini-Huygens mission to Saturn, including the spectacular launch, spacecraft assembly and the exciting trip to Saturn. |
| Full Description |
Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, Calif., manages the Cassini mission for NASA's Office of Space Science, Washington, D.C. Credit: NASA/JPL/University of Arizona (PIA02826) For higher resolution, click here., These two images, taken by NASA's Cassini spacecraft, show Jupiter in a near-infrared wavelength, and catch Europa, one of Jupiter's largest moons, at different phases. Cassini's narrow-angle camera took both images, the upper one from a distance of 69.9 million kilometers (43.4 million miles) on Oct. 17, 2000, and the lower one from a distance of 65.1 million kilometers (40.4 million miles) on Oct. 22, 2000. Both were taken at a wavelength of 727 nanometers, which is in the near-infrared region of the electromagnetic spectrum. The camera's 727-nanometer filter accepts only a narrow spectral range centered on a relatively strong absorption feature due to methane gas. In this spectral region, the amount of light reflected by Jupiter's clouds is only half that reflected in a nearby spectral region outside the methane band. The features that are brightest in these images are the highest and thickest clouds, such as the Great Red Spot and the band of clouds girding the equator, as these scatter sunlight back to space before it has a chance to be absorbed by the methane gas in the atmosphere. This stratigraphic effect can be seen even more prominently in an image released on Oct. 23, 2000, taken in the stronger methane band at 889 nanometers, in which the only bright features are the highest hazes over the equator, the poles and the Great Red Spot. By comparing images taken in the 727 nanometer filter with others taken at 889 nanometers and at a weaker methane band at 619 nanometers, researchers will probe the heights and thickness of clouds in Jupiter's atmosphere. Europa, a satellite of Jupiter about the size of Earth's Moon, is visible to the left of Jupiter in the upper image, and in front of the planet in the lower image. Another of Jupiter's Galilean satellites, Ganymede, which is larger than the planet Mercury, is to the right in the upper image, with brightness variations visible across its surface. In the upper image, Europa is caught entering Jupiter's shadow, and hence appears as a bright crescent, in the lower image, it is seen about one-and-a-half orbits later, in transit across the face of the planet. Because there is neither methane nor any strong absorber in this spectral region on the surface of Europa, it appears strikingly white and bright compared to Jupiter. Imaging observations of the moons Europa, Io and Ganymede entering and passing through Jupiter's shadow are planned for the two-week period surrounding Cassini's closest approach on Dec. 30, 2000. The purpose of these eclipse observations is to detect and measure the variability of emissions that arise from the interaction of the satellites' tenuous atmospheres with the charged particles trapped in Jupiter's magnetic field. At the times these images were taken, Cassini was about 3.3 degrees above Jupiter's equatorial plane, and the Sun-Jupiter-spacecraft angle was about 20 degrees. Cassini is a cooperative project of NASA, the European Space Agency and the Italian |
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Influence of Mimas
| Description |
Here on the Gallery page you can find the very latest images, videos and products from the Cassini-Huygens mission to Saturn, including the spectacular launch, spacecraft assembly and the exciting trip to Saturn. |
| Full Description |
Mimas, seen here beyond Saturn's rings, is a major sculptor of Saturn's rings. The 398-kilometer-wide (247-mile-wide) moon not only maintains the Cassini Division (not seen here), a gap wide enough to be visible from Earth through a small telescope, but it is also responsible for two of the thin, bright bands visible in this image near the rings' center, interior to the dark Encke Gap. Knots in the thin, twisted F ring also are easily visible here. The image was taken in visible light with the Cassini spacecraft narrow angle camera on Sept. 7, 2004, at a distance of 8.8 million kilometers (5.5 million miles) from Mimas and at a Sun-Mimas-spacecraft, or phase, angle of 84 degrees. The image scale is 53 kilometers (33 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo. For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the Cassini imaging team home page, http://ciclops.org . *Image Credit:* NASA/JPL/Space Science Institute |
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Pale Blue Orb (2)
| title |
Pale Blue Orb (2) |
| date |
09.15.2006 |
| description |
Not since NASA's Voyager 1 spacecraft saw our home as a pale blue dot from beyond the orbit of Neptune has Earth been imaged in color from the outer solar system. Now, Cassini casts powerful eyes on our home planet, and captures Earth, a pale blue orb -- and a faint suggestion of our moon -- among the glories of the Saturn system. Earth is captured here in a natural color portrait made possible by the passing of Saturn directly in front of the sun from Cassini's point of view. At the distance of Saturn's orbit, Earth is too narrowly separated from the sun for the spacecraft to safely point its cameras and other instruments toward its birthplace without protection from the sun's glare. The Earth-and-moon system is visible as a bright blue point on the right side of the image above center. Here, Cassini is looking down on the Atlantic Ocean and the western coast of north Africa. The phase angle of Earth, seen from Cassini is about 30 degrees. A magnified view of the image taken through the clear filter (monochrome) shows the moon as a dim protrusion to the upper left of Earth. Seen from the outer solar system through Cassini's cameras, the entire expanse of direct human experience, so far, is nothing more than a few pixels across. Earth no longer holds the distinction of being our solar system's only "water world," as several other bodies suggest the possibility that they too harbor liquid water beneath their surfaces. The Saturnian moon, Enceladus, is among them, and is also captured on the left in this image, with its plume of water ice particles and swathed in the blue E ring which it creates. Delicate fingers of material extend from the active moon into the E ring. See Ghostly Fingers of Enceladus [ http://saturn.jpl.nasa.gov/multimedia/images/image-details.cfm?imageID=2276 ], for a more detailed view of these newly-revealed features. The narrow tenuous G ring and the main rings are seen at the right. The view looks down from about 15 degrees above the un-illuminated side of the rings. Images taken using red, green and blue spectral filters were combined to create this view. The image was taken by the Cassini spacecraft wide-angle camera on Sept. 15, 2006, at a distance of approximately 2.1 million kilometers (1.3 million miles) from Saturn and at a sun-Saturn-spacecraft angle of almost 179 degrees. Image scale is approximately 250 kilometers (155 miles) per pixel. At this time, Cassini was nearly 1.5 billion kilometers (930 million miles) from Earth. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For, more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov ] . The Cassini imaging team homepage is at http://ciclops.org [ http://ciclops.org ] . Credit: NASA/JPL/Space Science Institute |
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Charon Discovery Image
| title |
Charon Discovery Image |
| date |
06.22.1978 |
| description |
On 22 June 1978, an astronomer at the U.S. Naval Observatory in Washington, D.C. was making routine measurements of photographic plates taken with the 1.55-meter (61-inch) Kaj Strand Astrometric Reflector at the USNO Flagstaff Station in Arizona. The purpose of these images was to refine the orbit of the far-flung planet Pluto to help compute a better ephemeris for this distant object. Astronomer James W. Christy had noticed that a number of the images of Pluto appeared elongated, but images of background stars on the same plate did not. Other plates showed the planet as a tiny, round dot. Christy examined a number of Pluto images from the USNO archives, and he noticed the elongations again. Furthermore, the elongations appeared to change position with respect to the stars over time. After eliminating the possibility that the elongations were produced by plate defects and background stars, the only plausible explanation was that they were caused by a previously unknown moon orbiting Pluto at a distance of about 19,600 kilometers (12,100 miles) with a period of just over six days. On 7 July 1978, the discovery was formally announced to the astronomical community and the world by the IAU Central Bureau for Astronomical Telegrams via IAU Circular 3241. The discovery received the provisional designation "1978 P 1", Christy proposed the name "Charon", after the mythological ferryman who carried souls across the river Acheron, one of the five mythical rivers that surrounded Pluto's underworld. Over the course of the next several years, another USNO astronomer, the late Robert S. Harrington, calculated that Pluto and its newly-found moon would undergo a series of mutual eclipses and occultations, beginning in early 1985. On 17 February 1985 the first successful observation of one of these transits was made at with the 0.9-meter (36-inch) reflector at the University of Texas McDonald Observatory, within 40 minutes of Harrington's predicted time. The IAU Circular announcing these confirming observations was issued on 22 February 1985. With this confirmation, the new moon was officially named Charon. Pluto was discovered at Lowell Observatory in 1930 by the late Clyde W. Tombaugh, an amateur astronomer from Kansas who was hired by the Observatory specifically to photograph the sky with a special camera and search for the planet predicted by the Observatory's founder, Percival Lowell. Lowell had deduced the existence of a "Planet X" by studying small anomalies in the orbits of Uranus and Neptune. As it turned out, Pluto's discovery was almost entirely serendipitous, Pluto's tiny mass was far too small to account for the anomalies, which were resolved when Voyager 2 determined more precise masses for Uranus and Neptune. The discovery of Charon has led to a much better understanding of just how tiny Pluto is. Its diameter is about 2274 km (1413 miles), and its mass is 0.25% of the mass of the Earth. Charon has a diameter of about 1172 kilometers (728, miles) and a mass of about 22% that of Pluto. The two worlds circle their common center of mass with a period of 6.387 days and are locked in a "super-synchronous" rotation: observers on Pluto's surface would always see Charon in the same part of the sky relative to their local horizon. Normally Pluto is considered the most distant world in the solar system, but during the period from January 1979 until February 1999 it was actually closer to the Sun than Neptune. It has the most eccentric and inclinced orbit of any of the major planets. This orbit won't bring Pluto back to its discovery position until the year 2178! *Image Credit*: U.S. Naval Observatory |
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Distant Saturn
| title |
Distant Saturn |
| date |
10.21.2002 |
| description |
Saturn appears serene and majestic in the first color composite made of images taken by NASA's Cassini spacecraft on its approach to the ringed planet, with arrival still 20 months away. The planet was 285 million kilometers (177 million miles) away from the spacecraft, nearly twice the distance between the Sun and Earth, when Cassini took images of it in various filters as an engineering test on Oct. 21, 2002. It is summer in Saturn's southern hemisphere. The Sun is a lofty 27 degrees below the equator and casts a semi-circular shadow of the planet on the rings. The shadow extends partway across the rings, leaving the outer A ring in sunlight. The last Saturn-bound spacecraft, Voyager 2, arrived in early northern spring. Many features seen in Voyager images -- spoke-like markings on the rings, clouds and eddies in the hazy atmosphere, ring-shepherding moons -- are not yet visible to Cassini. Titan, Saturn's largest moon, appears in the upper left. It is the only moon resolved from this distance. This composite uses a threefold enhancement in the brightness of Titan relative to the brightness of Saturn. Titan is a major attraction for scientists of the Cassini-Huygens mission. They will study its haze-enshrouded atmosphere and peer down, with special instrumentation, to its surface to look for evidence of organic processes similar to those that might have occurred on the early Earth, prior to the emergence of life. Cassini will enter orbit around Saturn on July 1, 2004. It will release a piggybacked probe, Huygens, which will descend through Titan's atmosphere on Jan. 14, 2005. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. Information about the mission is available online at http://saturn.jpl.nasa.gov . The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Office of Space Science, Washington, D.C. *Image Credit*: NASA/JPL/Southwest Research Institute |
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Mercury's Caloris Basin
| title |
Mercury's Caloris Basin |
| date |
03.28.1974 |
| description |
Mercury: The desert closest to the sun. Computer Photomosaic of the Caloris Basin The largest basin on Mercury (1300 km or 800 miles across) was named Caloris (Greek for "hot") because it is one of the two areas on the planet that face the Sun at perihelion. The Image Processing Lab at NASA's Jet Propulsion Laboratory produced this photomosaic using computer software and techniques developed for use in processing planetary data. The Mariner 10 spacecraft imaged the region during its initial flyby of the planet. The Mariner 10 spacecraft was launched in 1974. The spacecraft took images of Venus in February 1974 on the way to three encounters with Mercury in March and September 1974 and March 1975. The spacecraft took more than 7,000 images of Mercury, Venus, the Earth and the Moon during its mission. The Mariner 10 Mission was managed by the Jet Propulsion Laboratory for NASA's Office of Space Science in Washington, D.C. *Image Credit*: NASA |
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Hubble Uncovers Dust Disk ar
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| Title |
Hubble Uncovers Dust Disk around a Massive Black Hole |
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Hubble Confirms New Moons of
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| Title |
Hubble Confirms New Moons of Pluto |
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Hubble Sees 'Comet Galaxy' B
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| Title |
Hubble Sees 'Comet Galaxy' Being Ripped Apart By Galaxy Cluster |
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Hubble Sees Faintest Stars i
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| Title |
Hubble Sees Faintest Stars in a Globular Cluster |
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Solstice And Season's Eclips
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| Title |
Solstice And Season's Eclipse |
| Explanation |
Today the Sun reaches its southernmost point [ http://www-spof.gsfc.nasa.gov/stargaze/Sseason.htm ] in planet Earth's sky at 13:37 UT [ http://aa.usno.navy.mil/AA/faq/docs/UT.html ]. This celestial event is known as a solstice, marking the beginning of Summer [ http://antwrp.gsfc.nasa.gov/apod/ap951222.html ] in the Southern Hemisphere and Winter in the North. But this year, the solstice will be followed, on December 25th, by another geocentric celestial event [ http://aa.usno.navy.mil/AA/data/docs/EarthSeasons.html ] -- the last eclipse of the millennium [ http://www.usno.navy.mil/millennium/ ]! The Christmas day eclipse [ http://sunearth.gsfc.nasa.gov/eclipse/extra/ PSE2000Dec25.html ] will only be a partial one as the silhouetted disk of the Moon obscures the Sun's edge. Visible [ http://sunearth.gsfc.nasa.gov/eclipse/SEplot/ SE2000Dec25P.gif ] from much of Canada [ http://sunearth.gsfc.nasa.gov/eclipse/extra/ PSE2000Dec25city2/PSE2000Dec25city2.html ], The United States [ http://sunearth.gsfc.nasa.gov/eclipse/extra/ PSE2000Dec25city1/PSE2000Dec25city1.html ] and Mexico [ http://sunearth.gsfc.nasa.gov/eclipse/extra/ PSE2000Dec25city3/PSE2000Dec25city3.html ], the appearance of the partially eclipsed Sun might remind you of the last holiday cookie [ http://www.cs.cmu.edu/~mjw/recipes/cookies/cookie.html ] you took a bite from. Still, the exact timing and degree of the eclipse will depend very much on your location. This image, from an annular eclipse [ http://www.astrosurf.com/alphaweb/10mai94/ ] in 1994, shows the lunar disk covering around 55% of the Sun's diameter. It is representative of what could be seen from Washington D. C. during the December 25 eclipse maximum which, for that location, occurs at 12:41 PM ET. As always, if you view the eclipse be extremely careful [ http://www.mreclipse.com/Totality/ TotalityCh11.html#Intro ] to protect your eyes. |
|
Mercury's Caloris Basin
| Title |
Mercury's Caloris Basin |
| Description |
Mercury: Computer Photomosaic of the Caloris Basin The largest basin on Mercury (1300 km or 800 miles across) was named Caloris (Greek for "hot") because it is one of the two areas on the planet that face the Sun at perihelion. The Image Processing Lab at NASA's Jet Propulsion Laboratory produced this photomosaic using computer software and techniques developed for use in processing planetary data. The Mariner 10 spacecraft imaged the region during its initial flyby of the planet. The Mariner 10 spacecraft was launched in 1974. The spacecraft took images of Venus in February 1974 on the way to three encounters with Mercury in March and September 1974 and March 1975. The spacecraft took more than 7,000 images of Mercury, Venus, the Earth and the Moon during its mission. The Mariner 10 Mission was managed by the Jet Propulsion Laboratory for NASA's Office of Space Science in Washington, D.C. |
| Date |
01.11.2001 |
|
Distant Saturn Sighting
| Title |
Distant Saturn Sighting |
| Description |
Saturn appears serene and majestic in the first color composite made of images taken by NASA's Cassini spacecraft on its approach to the ringed planet, with arrival still 20 months away. The planet was 285 million kilometers (177 million miles) away from the spacecraft, nearly twice the distance between the Sun and Earth, when Cassini took images of it in various filters as an engineering test on Oct. 21, 2002. It is summer in Saturn's southern hemisphere. The Sun is a lofty 27 degrees below the equator and casts a semi-circular shadow of the planet on the rings. The shadow extends partway across the rings, leaving the outer A ring in sunlight. The last Saturn-bound spacecraft, Voyager 2, arrived in early northern spring. Many features seen in Voyager images -- spoke-like markings on the rings, clouds and eddies in the hazy atmosphere, ring-shepherding moons -- are not yet visible to Cassini. Titan, Saturn's largest moon, appears in the upper left. It is the only moon resolved from this distance. This composite uses a threefold enhancement in the brightness of Titan relative to the brightness of Saturn. Titan is a major attraction for scientists of the Cassini-Huygens mission. They will study its haze-enshrouded atmosphere and peer down, with special instrumentation, to its surface to look for evidence of organic processes similar to those that might have occurred on the early Earth, prior to the emergence of life. Cassini will enter orbit around Saturn on July 1, 2004. It will release a piggybacked probe, Huygens, which will descend through Titan's atmosphere on Jan. 14, 2005. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. Information about the mission is available online at http://saturn.jpl.nasa.gov . The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Office of Space Science, Washington, D.C. |
| Date |
11.01.2002 |
|
Europa Ice Floes
| Title |
Europa Ice Floes |
| Description |
Jupiter's moon Europa, as seen in this image taken June 27, 1996 by NASA's Galileo spacecraft, displays features in some areas resembling ice floes seen in Earth's polar seas. Europa, about the size of Earth's moon, has an icy crust that has been severely fractured, as indicated by the dark linear, curved, and wedged-shaped bands seen here. These fractures have broken the crust into plates as large as 30 kilometers (18.5 miles) across. Areas between the plates are filled with material that was probably icy slush contaminated with rocky debris. Some individual plates were separated and rotated into new positions. Europa's density indicates that it has a shell of water ice thicker than 100 kilometers (about 60 miles), parts of which could be liquid. Currently, water ice could extend from the surface down to the rocky interior, but the features seen in this image suggest that motion of the disrupted icy plates was lubricated by soft ice or liquid water below the surface at the time of disruption. This image covers part of the equatorial zone of Europa and was taken from a distance of 156,000 kilometers (about 96,300 miles) by the Solid-state Imaging Subsystem on the Galileo spacecraft. North is to the right and the sun is nearly directly overhead. The area shown is about 510 by 989 kilometers (310-by-600 miles), and the smallest visible feature is about 1.6 kilometers (1 mile) across. The Jet Propulsion Laboratory manages the Galileo mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web Galileo mission home page at http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at http:// www.jpl.nasa.gov/galileo/sepo. |
| Date |
02.25.1997 |
|
Four Galileo Views of Amalth
…
| Title |
Four Galileo Views of Amalthea |
| Description |
These four images of Jupiter's moon, Amalthea, were taken by Galileo's solid state imaging system at various times between February and June 1997. North is approximately up in all cases. Amalthea, whose longest dimension is approximately 247 kilometers (154 miles) across, is tidally locked so that the same side of the satellite always points towards Jupiter, similar to how the nearside of our own Moon always points toward Earth. In such a tidally locked state, one side of Amalthea always points in the direction in which Amalthea moves as it orbits about Jupiter. This is called the "leading side" of the moon and is shown in the top two images. The opposite side of Amalthea, the "trailing side," is shown in the bottom pair of images. The Sun illuminates the surface from the left in the top left image and from the right in the bottom left image. Such lighting geometries, similar to taking a picture from a high altitude at sunrise or sunset, are excellent for viewing the topography of the satellite's surface such as impact craters and hills. In the two images on the right, however, the Sun is almost directly behind the spacecraft. This latter geometry, similar to taking a picture from a high altitude at noon, washes out topographic features and emphasizes Amalthea's albedo (light/dark) patterns. It emphasizes the presence of surface materials that are intrinsically brighter or darker than their surroundings. The bright albedo spot that dominates the top right image is located inside a large south polar crater named Gaea. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech). This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. |
| Date |
11.13.1997 |
|
Icy Europa and similar scale
…
| Title |
Icy Europa and similar scales on Earth |
| Description |
This is the first in a series of products that compare images at increasing resolutions of various areas on Jupiter'sicy moon Europa [ http://photojournal.jpl.nasa.gov/catalog/PIA00539 ](top frame) to the same location on Earth, the San Francisco Bay area of California (bottom frame). Both images show areas of roughly equal size, 252 by 393 kilometers (157 by 244 miles), and resolution, 630 meters (690 yards). This means that the smallest identifiable feature is less than a mile across (2 pixels wide). North is to the top of the picture. The sun illumination from the right in the Europa image reveals several ridges crossing the scene, plateaus commonly several miles (10 km) across, and patches of smooth, low-lying darker materials. No prominent impact craters are visible, indicating the surface in this location is not geologically ancient. Some ridges have gaps, and subtle textural differences in these areas indicate that missing ridge segments probably were swept away by volcanic flows. The flow deposits are probably composed mainly of water ice, the chief constituent of the surface of Europa. The Earth based image (lower frame) covers an area stretching from San Francisco Bay (top left) to the Nevada border (top right) and from Mono Lake in (top center) to the Mojave Desert (bottom right). Other predominant geographic features include the snow capped Sierra Nevada Mountains and California's Great Central Valley (center frame). The Europa image was obtained from a range of 62089 kilometers (39028 miles) by the Solid State Imaging (CCD) system aboard NASA's Galileo spacecraft on December 19th, 1996 (Universal Time). The San Francisco Bay area image, from the NOAA satellite's Advanced Very High Resolution Radiometer (AVHRR) instrument, has been reprocessed to roughly match Galileo's resolution so as to offer a sense of the size of the features visible on Europa's surface. The Jet Propulsion Laboratory, Pasadena, CA, manages the mission for NASA's Office of Space Science, Washington D.C. This image and other images and data received from Galileo are posted on the World Wide Web Galileo mission home page at: http://galileo.jpl.nasa.gov. |
| Date |
05.19.1997 |
|
Jupiter's Magnetosphere Made
…
| Title |
Jupiter's Magnetosphere Made Visible |
| Description |
The vast magnetosphere of charged particles whirling around Jupiter, normally invisible, can be imaged by a new type of instrument aboard NASA's Cassini spacecraft and is seen here. Three features are sketched in for context: a black circle showing the size of Jupiter, lines of Jupiter's magnetic field, and a cross-section of the Io torus, a doughnut-shaped ring of charged particles that originate from volcanic eruptions on Jupiter's moon Io and circle Jupiter at about the orbit of Io. Jupiter's magnetosphere is the largest object in the solar system. If it glowed in wavelengths visible to the eye, it would appear two to three times the size of the Sun or Moon to viewers on Earth. Cassini's ion and neutral camera detects neutral atoms expelled from the magnetosphere, deriving information about their source. This image was taken shortly after Cassini's closest approach to Jupiter, about 10 million kilometers (6 million miles) from the planet on Dec. 30, 2000. For more information about the Saturn-bound spacecraft and its observations of Jupiter, see the Cassini home page,http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov ]. Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini mission for NASA's Office of Space Science, Washington, D.C. |
| Date |
02.27.2002 |
|
Jupiter's Main Ring and Halo
| Title |
Jupiter's Main Ring and Halo |
| Description |
The top and bottom panels show a mosaic of images of Jupiter's rings taken by NASA's Galileo spacecraft. Jupiter is to the right of this mosaic, and different brightness scales accent different parts of the ring system. Jupiter's ring system has three parts -- a flat main ring, a halo inside the main ring shaped like a double-convex lens, and the gossamer ring outside the main ring. In the top view, a faint mist of particles is seen above and below the main ring. This vertically extended "halo" is unusual in planetary rings, and is caused by electromagnetic forces pushing the smallest grains, which carry electric charges, out of the ring plane. [figure removed for brevity, see original site] *Development of Jupiter's Main Ring and Halo* Jupiter's main ring is a thin sheet of material encircling the planet. The near and far arms of this ring extend horizontally across the mosaic, joining together at the ring's ansa, the portion visible on the sides of Jupiter, on the figure's far left side. In the bottom view, some radial structure is visible across the ring's ansa. The diffuse innermost boundary begins at approximately 122,500 kilometers (about 76,100 miles). The main ring's outer radius is at about 128,940 kilometers (80,120 miles), very close to the orbit of the Jovian moon Adrastea (128,980 kilometers or 80,140 miles). The brightness of the main ring drops markedly at about 127,850 kilometers (79,440 miles), very near the orbit of another moon, Metis, at 127,978 kilometers (79,521 miles). Jupiter's four small satellites, Metis, Adrastea, Amalthea and Thebe, affect the structure of the huge planet's tenuous rings. [figure removed for brevity, see original site] *Jupiter's Main Ring and Halo* These images were taken through the clear filter of Galileo's onboard solid state imaging camera system on November 9, 1996. The resolution is approximately 24 kilometers (14 miles) per picture element along Jupiter's rings. Because the spacecraft was only about 0.5 degrees above the ring plane, the image is highly foreshortened vertically. The images were obtained when Galileo was in Jupiter's shadow, peering back toward the Sun, when the ring was approximately 2.3 million kilometers (1.4 million miles) away. The view of Earth's moon in the explanatory graphics was created from images returned by the Clementine lunar orbiter, launched in 1994 by NASA and the Ballistic Missile Defense Organization. JPL manages the Galileo mission for NASA's Office of Space Science, Washington, DC. The images are posted on the Internet athttp://photojournal.jpl.nasa.gov/ [ http://photojournal.jpl.nasa.gov/ ]and athttp://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at:http://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ]. |
| Date |
09.15.1998 |
|
First HiRISE image of Mars
| title |
First HiRISE image of Mars |
| Description |
. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems is the prime contractor for the project and built the spacecraft. The HiRISE camera was built by Ball Aerospace and Technology Corporation and is operated by the University of Arizona. Credit: NASA/JPL/University of Arizona, The first image of Mars by the High Resolution Imaging Science Experiment (HiRISE) on NASA's Mars Reconnaissance Orbiter shows a story of geologic change in the eastern Bosporos Planum region. Old stream valleys cut into the flanks of a gently sloping mountain range in the center of the image. Layers of smooth-textured deposits have mantled the stream valleys and many impact craters. Wind and sublimation of water or carbon dioxide ice have partially eroded patches of the smooth-textured deposits, leaving behind areas of layered and hummocky terrain. A prominent ridge that extends from the top to the bottom of the image dominates the scene. This ridge formed above a thrust fault, a type of fault that occurs when the surface of a planet is compressed. On planetary surfaces, such fault-related ridges are termed "wrinkle ridges." They are commonly observed on Mars, as well as on Earth's moon and on Venus and Mercury. The wrinkle ridge imaged here is named Ogygis Rupes. This wrinkle ridge has deformed several valleys and impact craters. Throughout the scene, geologically young sand dunes are present within stream valleys and some impact craters. The area is also sprinkled with many small young impact craters, which are distinguished by sharp crater rims and bright or dark halos of ejected material. This image demonstrates how a single HiRISE image can capture a multitude of geologic processes. Image AEB_000001_0000_Red was taken by HiRISE on March 24, 2006. The image is centered at 33.65 degrees south latitude, 305.07 degrees east longitude. It is oriented such that north is 7 degrees to the left of up. The range to the target was 2,493 kilometers (1,549 miles). At this distance the image scale is 2.49 meters (8.17 feet) per pixel, so objects as small as 7.5 meters (24.6 feet) are resolved. In total this image is 49.92 kilometers (31.02 miles) or 20,081 pixels wide and 23.66 kilometers (14.70 miles) or 9,523 pixels long. The image was taken at a local Mars time of 07:33 and the scene is illuminated from the upper right with a solar incidence angle of 78 degrees, thus the sun was 12 degrees above the horizon. At an Ls of 29 degrees (with Ls an indicator of Mars' position in its orbit around the sun), the season on Mars is southern autumn. Images from the High Resolution Imaging Science Experiment and additional information about the Mars Reconnaissance Orbiter are available online at: http://www.nasa.gov/mro [ http://www.nasa.gov/mro ] or http://HiRISE.lpl.arizona.edu [ http://HiRISE.lpl.arizona.edu ]. For information about NASA and agency programs on the Web, visit: http://www.nasa.gov [ http://www.nasa.gov ] |
|
June 10 Annular Solar Eclips
…
nasa, nasaimageofthedaygalle
…
On June 10, 2002, the moon o
…
PIA03712
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2002-06-10 |
| creator |
NASA -- Image provided by NASA/GSFC/LaRC/JPL, MISR Team |
| identifier |
PIA03712 |
|
Europa, Ganymede, and Callis
…
PIA01656
Jupiter
Solid-State Imaging
| Title |
Europa, Ganymede, and Callisto: Surface comparison at high spatial resolution |
| Original Caption Released with Image |
Ganymede's youngest large craters would have been created only about one billion years ago. Europa's surface in this model should be very young, with this satellite being geologically quite active even today. The images were taken by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft. They were processed by the Institute of Planetary Exploration of the German Aerospace Center (DLR) in Berlin, Germany, and scaled to a size of 150 meters per pixel (m/pixel). North is up in all images. The spatial resolution of the original data was 180 m/pixel for Europa and Ganymede and 90 m/pixel for Callisto. The Europa image was taken during Galileo's 6th orbit, the Ganymede image during the 7th, and the Callisto image during the 10th orbit. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ]., These images show a comparison of the surfaces of the three icy Galilean satellites, Europa, Ganymede, and Callisto, scaled to a common resolution of 150 meters per picture element (pixel). Despite the similar distance of 0.8 billion kilometers to the sun, their surfaces show dramatic differences. Callisto (with a diameter of 4817 kilometers) is "peppered" by impact craters, but is also covered by a dark material layer of so far unknown origin, as seen here in the region of the Asgard multi-ring basin. It appears that this layer erodes or covers small craters. Ganymede's landscape is also widely formed by impacts, but different from Callisto, much tectonic deformation can be observed in the Galileo images, such as these of Nicholson Regio. Ganymede, with a diameter of 5268 kilometers (one-and-a-half times larger than the Earth's moon), is the largest moon in the solar system. Contrary to Ganymede and Callisto, Europa (diameter 3121 kilometers) has a sparsely cratered surface, indicating that geologic activity took place more recently. Globally, ridged plains and the so-called "mottled terrain" are the main landforms. In the high-resolution image presented here showing the area around the Agave and Asterius dark lineaments, older ridges dominate the surface, while a small part of the younger mottled terrain is visible to the lower left of the image center. While all three moons are believed to be nearly as old as the solar system (4.5 billion years), the age of the surfaces, i.e. the time since the last major geologic activity took place, is still subject to debate. Without having surface samples in hand, the only method to roughly determine a planet's or satellite's geologic surface age is by crater counting. However, assumptions about the impactor fluxes must be made based on theoretical models and possible observations of candidate impactors such as asteroids and comets. Asteroids should have been very common in the early days of the solar system, but this source should have been largely exhausted by about 3.8 billion years before present. For comets, the impactor flux is believed to be rather constant throughout the whole lifetime of the solar system, meaning that the probability of an impact of a large comet is similar today as it was, say, four billion years ago. Assuming the asteroids have been the dominant bodies that impacted the Galilean satellites (which is believed to be the case on the Moon, the Earth, and other inner solar system bodies as well as within the asteroid belt itself), the surfaces of Ganymede and Callisto must be old, roughly four billion years. In this case, the Europan surface would by comparison have a mean age of one-hundred to several-hundred million years. Low-level geologic activity on Europa might be possible, but Ganymede and Callisto should be geologically dead. Assuming on the other hand that comets have been the main impactors in the Jovian system, Callisto's surface would still be determined to be old, but |
|
Europa and Callisto under th
…
PIA02861
Sol (our sun)
Imaging Science Subsystem
| Title |
Europa and Callisto under the watchful gaze of Jupiter |
| Original Caption Released with Image |
One moment in an ancient, orbital dance is caught in this color picture taken by NASA's Cassini spacecraft on Dec. 7, 2000, just as two of Jupiter's four major moons, Europa and Callisto, were nearly perfectly aligned with each other and the center of the planet. The distances are deceiving. Europa, seen against Jupiter, is 600,000 kilometers (370,000 miles) above the planet's cloud tops. Callisto, at lower left, is nearly three times that distance from the cloud tops. Europa is a bit smaller than Earth's Moon and has one of the brightest surfaces in the solar system. Callisto is 50 percent bigger -- roughly the size of Saturn's largest satellite, Titan -- and three times darker than Europa. Its brightness had to be enhanced in this picture, relative Europa's and Jupiter's, in order for Callisto to be seen in this image. Europa and Callisto have had very different geologic histories but share some surprising similarities, such as surfaces rich in ice. Callisto has apparently not undergone major internal compositional stratification, but Europa's interior has differentiated into a rocky core and an outer layer of nearly pure ice. Callisto's ancient surface is completely covered by large impact craters: The brightest features seen on Callisto in this image were discovered by the Voyager spacecraft in 1979 to be bright craters, like those on our Moon. In contrast, Europa's young surface is covered by a wild tapestry of ridges, chaotic terrain and only a handful of large craters. Recent data from the magnetometer carried by the Galileo spacecraft, which has been in orbit around Jupiter since 1995, indicate the presence of conducting fluid, most likely salty water, inside both worlds. Scientists are eager to discover whether the surface of Saturn's Titan resembles that of Callisto or Europa, or whether it is entirely different when Cassini finally reaches its destination in 2004. Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini mission for NASA's Office of Space Science, Washington, D.C. |
|
The Valhalla Multi-ring Stru
…
PIA01649
Jupiter
Solid-State Imaging
| Title |
The Valhalla Multi-ring Structure on Callisto |
| Original Caption Released with Image |
These images of Callisto, the outermost of the Galilean satellites of Jupiter, reveal a surface characterized by impact craters. The global view (lower left) is dominated by a large bulls-eye feature, the Valhalla multi-ring structure, consisting of a bright inner region about 600 kilometers (370 miles) across. Valhalla's 4,000 kilometer(2,500 mile) diameter make it one of the largest impact features in the solar system. Callisto is 4,800 kilometers (3,000 miles) in diameter. In this global view, the sun illuminates the surface from near the center, in the same way a full moon is seen from Earth when illuminated by the sun. The image on the right shows part of Valhalla at moderate resolution. At this resolution, the surface is appears to be somewhat smooth, with a lack of numerous small impact craters. Valhalla's outer rings are clearly seen to consist of troughs which could be fractures in the crust which resulted from the impact. The bright central plains possibly were created by the excavation and ejection of "cleaner" ice or liquid water from beneath the surface, with a fluid-like massfilling the crater bowl after impact. North is to the top of the picture. For the moderate resolution view on the right, the sun illuminates the surface from the left and the resolution is approximately 400 meters per picture element. The images were obtained on June 25, 1997 by the solid state imaging (SSI)system on NASA's Galileo spacecraft at a range of about 40,000 kilometers(25,000 miles) from Callisto during Galileo's ninth orbit of Jupiter. The global image on the left is centered at 0.5 degrees south latitude and 56 degrees longitude. The resolution is 14 kilometers per picture element. The images were obtained on November 5, 1997 at a range of 68,400 kilometers(42,400 miles) during Galileo's eleventh orbit of Jupiter. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URLhttp://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at URLhttp://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ] |
|
Influence of Mimas
PIA06509
Saturn
Imaging Science Subsystem -
…
| Title |
Influence of Mimas |
| Original Caption Released with Image |
Mimas, seen here beyond Saturn's rings, is a major sculptor of Saturn's rings. The 398-kilometer-wide (247-mile-wide) moon not only maintains the Cassini Division (not seen here), a gap wide enough to be visible from Earth through a small telescope, but it is also responsible for two of the thin, bright bands visible in this image near the rings' center, interior to the dark Encke Gap. Knots in the thin, twisted F ring also are easily visible here. The image was taken in visible light with the Cassini spacecraft narrow angle camera on Sept. 7, 2004, at a distance of 8.8 million kilometers (5.5 million miles) from Mimas and at a Sun-Mimas-spacecraft, or phase, angle of 84 degrees. The image scale is 53 kilometers (33 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Office of Space Science, Washington, D.C. The Cassini orbiter and its two onboard cameras, were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo. For more information, about the Cassini-Huygens mission visit, http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov/ ] and the Cassini imaging team home page, http://ciclops.org [ http://ciclops.org/ ]. |
|
Mimas...and Titan Beyond
PIA07666
Sol (our sun)
Imaging Science Subsystem -
…
| Title |
Mimas...and Titan Beyond |
| Original Caption Released with Image |
Titan, Saturn's largest moon, and Mimas, closer but much smaller on the right, are seen together in this view from Cassini. Titan's gravity is weaker than Earth's, so the moon's atmosphere is quite extended --- a quality hinted at in this view. Part of Mimas' dark side is illuminated by reflected light from nearby Saturn. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Dec. 3, 2005, at a distance of approximately 3.6 million kilometers (2.2 million miles) from Titan (5,150 kilometers, or 3,200 miles across) and 2.5 million kilometers (1.6 million miles) from Mimas (397 kilometers, or 247 miles across). Both moons are seen at a Sun-moon-spacecraft angle, or phase angle, of 110 degrees. The image scale is 22 kilometers (14 miles) per pixel on Titan and 15 kilometers (9 miles) per pixel on Mimas. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov ]. The Cassini imaging team homepage is at http://ciclops.org [ http://ciclops.org ]. |
|
Waning Iapetus
PIA06145
Saturn
Imaging Science Subsystem -
…
| Title |
Waning Iapetus |
| Original Caption Released with Image |
These spectacular Cassini images of Saturn's moon Iapetus show an enticing world of contrasts. These are the sharpest views of Iapetus from Cassini so far, and they represent better resolution than the best images of this moon achieved by NASA's Voyager spacecraft. Images obtained using ultraviolet (centered at 338 nanometers), green (568 nanometers) and infrared (930 nanometers) filters were combined to produce the enhanced color views at left and center, the image at the right was obtained in visible white light. The images on the bottom row are identical to those on top, with the addition of an overlying coordinate grid. These views show parts of the moon's anti-Saturn side--the side that faces away from the ringed planet--which will not be imaged again by Cassini until Sept., 2007. In the central view, part of the moon's eastern edge was not imaged and appears to be cut off. With a diameter of 1,436 kilometers (892 miles), Iapetus is Saturn's third largest moon. It is famous for the dramatic contrasts in brightness on its surface--the leading hemisphere is as dark as a freshly-tarred street, and the trailing hemisphere and poles almost as bright as snow. Many impact craters can be seen in the bright terrain and in the transition zone between bright and dark, and for the first time in parts of the dark terrain. Also visible is a line of mountains that appear as a string of bright dots in the two color images at left, and on the eastern limb in the image at right. These mountains were originally detected in Voyager images, and might compete in height with the tallest mountains on Earth, Jupiter's moon Io and possibly even Mars. Further observations will be required to precisely determine their heights. Interestingly, the line of peaks is aligned remarkably close to the equator of Iapetus. The large circular feature rotating into view in the southern hemisphere is probably an impact structure with a diameter of more than 400 kilometers (250 miles), and was first seen in low-resolution Cassini images just two months earlier. Theses images were taken with the Cassini spacecraft narrow angle camera between Oct, 15 and 20, 2004, at distances of 1.2, 1.1 and 1.3 million kilometers (746,000, 684,000 and 808,000 miles) from Iapetus, respectively. The Sun-Iapetus-spacecraft, or phase, angle changes from 88 to 144 degrees across the three images. The image scale is approximately 7 kilometers (4.5 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Office of Space Science, Washington, D.C. The Cassini orbiter and its two onboard cameras, were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo. For more information, about the Cassini-Huygens mission, visit, http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov/ ] and the Cassini imaging team home page, http://ciclops.org [ http://ciclops.org/ ]. |
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Io Eclipse/Volcanic Eruption
PIA00704
Sol (our sun)
Solid-State Imaging
| Title |
Io Eclipse/Volcanic Eruption |
| Original Caption Released with Image |
This image was acquired while Io was in eclipse (in Jupiter's shadow) during Galileo's eighth orbit, and reveals several dynamic processes. The most intense features are red, while glows of lesser intensity are yellow or green, and very faint glows appear blue in this color-coded image. The small red or yellow spots mark the sites of high-temperature magma erupting onto the surface in lava flows or lava lakes. This image reveals a field of bright spots near Io's sub-Jupiter point (right-hand side of image). The sub-Jupiter hemisphere always faces Jupiter just as the Moon's nearside always faces Earth. There are extended diffuse glows on the equatorial limbs or edges of the planet (right and left sides). The glow on the left is over the active volcanic plume Prometheus, but whereas Prometheus appears to be 75 kilometers (46.6 miles) high in reflected light, here the diffuse glow extends about 800 kilometers (497 miles) from Io's limb. This extended glow indicates that gas or small particles reach much greater heights than the dense inner plume. The diffuse glow on the right side reaches a height of 400 kilometers (249 miles), and includes a prominence with a plume-like shape. However, no volcanic plume has been seen at this location in reflected light. This type of observation is revealing the relationships between Io's volcanism, atmosphere and exosphere. Taken on May 6, 1997, north is toward the top. The image was taken with the clear filter of the solid state imaging (CCD) system on NASA's Galileo spacecraft at a range of 1.8 million kilometers (1.1 million miles). The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech). This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo |
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Global Color Variations on C
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PIA01298
Jupiter
Solid-State Imaging
| Title |
Global Color Variations on Callisto |
| Original Caption Released with Image |
Jupiter's icy moon Callisto is shown in approximate natural color (left) and in false color to enhance subtle color variations (right). This image of Callisto's Jupiter-facing hemisphere shows the ancient, multi-ring impact structure Valhalla just above the center of the image. Valhalla, possibly created by a large asteroid or comet which impacted Callisto, is the largest surface feature on this icy moon. Valhalla consists of a bright inner region, about 600 kilometers (360 miles) in diameter surrounded by concentric rings 3000 to 4000 kilometers (1800-2500 miles) in diameter. The bright central plains were possibly created by the excavation and ejection of "cleaner" ice from beneath the surface, with a fluid-like mass (impact melt) filling the crater bowl after impact. The concentric rings are fractures in the crust resulting from the impact. The false color in the right image shows new information, including ejecta from relatively recent craters, which are often not apparent in the natural color image. The color also reveals a gradual variation across the moon's hemisphere, perhaps due to implantation of materials onto the surface from space. These color images were obtained with the 1 micrometer (infrared), green, and violet filters of the Solid State Imaging (SSI) system on NASA's Galileo spacecraft. The false color is created from ratios of infrared/violet and its inverse (violet/infrared) which are then combined so the infrared/violet, green, and violet/infrared are assigned to red, green, and blue in a composite product. North is to the top of the picture and the sun illuminates the surface from near the center, in the same way a full moon is seen from Earth when illuminated by the sun. The image, centered at 0.5 degrees south latitude and 56.3 degrees longitude, covers an area about 4800 by 4800 kilometers. The resolution is 14 kilometers per picture element. The images were taken on November 5, 1997 at a range of 68,400 kilometers (41,000 miles) during Galileo's eleventh orbit of Jupiter. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech). This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo |
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Pre-Dawn Temperatures on Gan
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PIA01145
Jupiter
Photopolarimeter-Radiometer
| Title |
Pre-Dawn Temperatures on Ganymede |
| Original Caption Released with Image |
This infrared image of Jupiter's moon Ganymede, showing heat radiation from its surface at a wavelength of 27 microns (millionths of a meter), provides the best view yet of pre-dawn temperatures on Ganymede. Temperatures, derived from the brightness of the infrared radiation, can be determined from the colors by reference to the scale at the bottom of the image. The image, taken by NASA's Galileo spacecraft, shows half of Ganymede's disk as seen by the approaching spacecraft. Longitudes covered range from 340 on the right of the image, through longitude zero (the direction facing Jupiter) to longitude 60 near Ganymede's limb on the left. The morning terminator, near longitude 15, curves through the middle of the image, separating areas experiencing the last hours of the long (3.5 Earth day) Ganymede night, on the left, from areas that are warming up in the morning sunshine, on the right. Ganymede's north pole is in the upper right corner of the image, and the south pole is in the lower right. Ganymede rotates from left to right. Nighttime temperatures, shown in blue and purple colors, are in the range 85 - 100 Kelvin (-306 to -279 F). The surface cools steadily during the night, so the warmest nighttime temperatures are on the left side of the disk, and temperatures drop towards the dawn terminator on the right, before warming rapidly once the sun rises (the red, yellow and white areas on the far right). Study of the rate of nighttime cooling and the rate of post-sunrise warming, will provide information about Ganymede's surface properties. The image was taken with Galileo's PPR (Photopolarimeter-Radiometer) instrument on the spacecraft's seventh orbit around Jupiter, from a range of about 190,000 kilometers (118,060 miles). Surface temperatures derived from the strength of infrared radiation, as was done here, are called "brightness temperatures", and may be slightly in error. The PPR instrument builds up an image by slowly scanning across the target over a period of up to one hour. The motion of Galileo relative to Ganymede during this time causes distortions in the satellite shape on the image, which therefore appears slightly non-circular. The small overlapping circles that make up the image show the size of the area, about 450 kilometers (280 miles) across, covered by each individual PPR measurement. Blue spots in the dark sky in the left-hand portion of the image are due to noise. JPL manages the Galileo mission for NASA's Office of Space Science, Washington, D.C. |
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Jupiter's Main Ring and Halo
PIA01622
Jupiter
Solid-State Imaging
| Title |
Jupiter's Main Ring and Halo |
| Original Caption Released with Image |
The top and bottom panels show a mosaic of images of Jupiter's rings taken by NASA's Galileo spacecraft. Jupiter is to the right of this mosaic, and different brightness scales accent different parts of the ring system. Jupiter's ring system has three parts -- a flat main ring, a halo inside the main ring shaped like a double-convex lens, and the gossamer ring outside the main ring. In the top view, a faint mist of particles is seen above and below the main ring. This vertically extended "halo" is unusual in planetary rings, and is caused by electromagnetic forces pushing the smallest grains, which carry electric charges, out of the ring plane. [ http://photojournal.jpl.nasa.gov/figures/magforce1.html ] Development of Jupiter's Main Ring and Halo Jupiter's main ring is a thin sheet of material encircling the planet. The near and far arms of this ring extend horizontally across the mosaic, joining together at the ring's ansa, the portion visible on the sides of Jupiter, on the figure's far left side. In the bottom view, some radial structure is visible across the ring's ansa. The diffuse innermost boundary begins at approximately 122,500 kilometers (about 76,100 miles). The main ring's outer radius is at about 128,940 kilometers (80,120 miles), very close to the orbit of the Jovian moon Adrastea (128,980 kilometers or 80,140 miles). The brightness of the main ring drops markedly at about 127,850 kilometers (79,440 miles), very near the orbit of another moon, Metis, at 127,978 kilometers (79,521 miles). Jupiter's four small satellites, Metis, Adrastea, Amalthea and Thebe, affect the structure of the huge planet's tenuous rings. [ http://photojournal.jpl.nasa.gov/figures/mainring.html ] Jupiter's Main Ring and Halo These images were taken through the clear filter of Galileo's onboard solid state imaging camera system on November 9, 1996. The resolution is approximately 24 kilometers (14 miles) per picture element along Jupiter's rings. Because the spacecraft was only about 0.5 degrees above the ring plane, the image is highly foreshortened vertically. The images were obtained when Galileo was in Jupiter's shadow, peering back toward the Sun, when the ring was approximately 2.3 million kilometers (1.4 million miles) away. The view of Earth's moon in the explanatory graphics was created from images returned by the Clementine lunar orbiter, launched in 1994 by NASA and the Ballistic Missile Defense Organization. JPL manages the Galileo mission for NASA's Office of Space Science, Washington, DC. The images are posted on the Internet at http://photojournal.jpl.nasa.gov/ [ http://photojournal.jpl.nasa.gov/ ] and at http://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at: http://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ]. |
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